*{
    box-sizing: border-box;
    padding: 0;
    margin: 0;
    font-weight: bold;
}

        nav{
            background-color: #101856;
            z-index: 9999;
            position: fixed;
            top: 0;
            width: 100%;
            display: flex;
            height: 80px;
            justify-content:space-around;
            align-items: center;
            box-shadow: 0 2px 10px rgba(0,0,0,0.3);
            
            
        }
        .logo img{
            width: 100px;
            height: 100px;
        }
        .menu{
            list-style: none;
            display: flex;
            margin-right: 20px;
            gap: 20px;
            margin-top: 20px;
            li{
                font-weight: bold;
                
            }
            a{
                text-decoration: none;
                color: rgb(255, 255, 255);
                font-family: 'Phetsarath OT';
                font-size: 15px;

            }

        }
   .menu a:hover{
         color: #0300c5;
         border-bottom: 2px solid #0300c5;

        }
        .icons{
            display: flex;
            gap: 20px;
            margin-right: 20px;
        }
        .icons a img{
            width: 30px;
            height: 30px;
            border-radius: 50%;
            background-color: rgba(136, 136, 136, 0.493);
            padding: 5px;
        }
        .icons a img:hover{
            background-color:#6690ff;
        }
        .a1{
            width: 100%;
            height: 350px;
            background-color: #261fb3;
            border-radius: 0px 0px 1000px 0px;
            border-bottom: 200px ridge darkblue;
            margin-top: 80px;
            font-family: 'Phetsarath OT'; 
            padding-top: 80px;
            text-align: center;
            position: relative;
            z-index: 1;
        }
        .a1 h1{
            color: rgb(255, 255, 255);
            font-size: 30px;


        }
        .a2{
            display: flex;
            justify-content: space-around;
            font-family: 'Phetsarath OT';
            margin-top: 100px;
        }
        .a3 .img1{
            width: 150px;
            height: 150px;
            background-color: #000dc9;
            border-radius: 10px;
            margin-top: 50px;
            border-bottom: #101856 20px double;
            border-top: #101856 20px double;
            border-left: #101856 20px double;
            border-right: #101856 20px double;

        }
        .a3 .img2{
            width: 300px ;
            height: 300px;
            border-bottom: #101856   30px double;
            border-top: #101856 30px double;
            border-left: #101856 30px double;
            border-right: #101856 30px double;
            border-radius: 10px;
            margin-left: 30px;
            

            

        }
        .a4{
            display: grid;
            width: 600px;
        }
        .a5{
            margin-top: 50px;
            background-color: #ffffff;
             border-top: #101856 50px ridge;
             border-bottom: #09188b 50px ridge;
             height: 400px;
             border-radius: 300px 0px 0px 0px;

        }
        .a6{
            display: flex;
            justify-content: space-around;
            margin-left: 170px;
            margin-top: 30px;
            

        }
        .a7{
            width: 400px;
            height: 200px;
            background-color: rgba(240, 248, 255, 0);
            font-family: 'Phetsarath OT';
            font-weight: bold;
            color: rgb(0, 18, 121);
        }
        .a8{
            margin-left: 200px;
            font-family: 'Phetsarath OT';
            color: rgb(0, 18, 121);

        }
        .a8 h5{
            font-weight: bold;
        }

           footer{
            width: 100%;
            height: 400px;
            background-color: #101856;
            position: relative;

        }
        .box-9{
            display: flex;
            background-color: #4ddbdb00;
            width: 100%;
            height: 400px;
            justify-content: space-between;
            padding-right: 100px;

        }
        .box-10{
            width: 300px;
            height: 300px;
            
        }
        .box-10 img{
            width: 150px;
            height: 150px;
            margin-left: 105px;
        }
        .box-10 p{
            width: 300px;
            margin-left: 50px;
            color: #fff;
            margin-top: -20px;
            font-family:'Phetsarath OT' ;

        }
        .box-11{
            font-family:'Phetsarath OT' ;
            margin-top: 50px;
            color: #fff;
            font-size: 18px;
            margin-right: 50px;
            
        }
        .box-12{
            font-family:'Phetsarath OT' ;
            margin-top: 50px;
            margin-right: 10px;
            color: #fff;
            font-size: 18px;
        }
        .box-13{
            display: flex;
            justify-content: space-between;
        }
        .box-14{
            font-size: 20px;
            color: rgb(255, 255, 255);
            margin-left: 40px;
            margin-top: -130px;
            font-family:'Phetsarath OT' ;

        }
        .box-15{
            margin-right: 100px;
            margin-top: -90px;
        }
        .box-15 img{
            width: 45px;
            height: 45px;
            background-color: #57575794;border-radius: 50%;
            padding: 5px;
        }
        .footer-1{
            width: 100%;
            height: 50px;
            background-color: #101856;
            position: relative;
            align-items: center;
            display: flex;
            justify-content: space-between;
            padding-right: 100px;
            font-family:'Phetsarath OT' ;
            padding-left: 40px;
            color: #ffffff;
        }
        .footer-1 a{
                color: #ffffff;
            }


/* ======================================== */
/* เริ่มส่วน RESPONSIVE ที่เพิ่มเข้ามาใหม่ */
/* ======================================== */

/* Tablet - หน้าจอขนาดกลาง (768px - 1024px) */
@media screen and (max-width: 1024px) {
    html, body {
        overflow-x: hidden;
        width: 100%;
    }
    
    nav {
        height: auto;
        min-height: 70px;
        padding: 10px 20px;
        flex-wrap: wrap;
        justify-content: space-between;
        gap: 10px;
    }
    
    .logo img {
        width: 70px;
        height: 70px;
    }
    
    .menu {
        gap: 12px;
        margin: 5px 0;
        flex-wrap: wrap;
    }
    
    .menu a {
        font-size: 13px;
        padding: 5px 8px;
    }
    
    .icons {
        gap: 12px;
        margin: 5px 0;
    }
    
    .a1 {
        height: 320px;
        margin-top: 90px;
        border-radius: 0px 0px 500px 0px;
        border-bottom: 120px ridge darkblue;
        padding-top: 90px;
    }
    
    .a1 h1 {
        font-size: 26px;
        padding: 0 20px;
    }
    
    .a2 {
        flex-direction: column;
        align-items: center;
        margin-top: 60px;
        gap: 30px;
        padding: 0 20px;
    }
    
    .a3 {
        display: flex;
        flex-direction: column;
        align-items: center;
        width: 100%;
    }
    
    .a3 .img1 {
        width: 130px;
        height: 130px;
        border: #101856 15px double;
        margin-top: 30px;
    }
    
    .a3 .img2 {
        width: 260px;
        height: 260px;
        border: #101856 25px double;
        margin-left: 0;
        margin-top: 25px;
    }
    
    .a4 {
        width: 95%;
        max-width: 600px;
        text-align: center;
        padding: 0 20px;
    }
    
    .a4 h1 {
        font-size: 24px;
    }
    
    .a4 h2, .a4 h3 {
        font-size: 18px;
    }
    
    .a5 {
        height: auto;
        padding: 40px 20px;
        border-radius: 200px 0px 0px 0px;
        border-top: 35px ridge #101856;
        border-bottom: 35px ridge #09188b;
    }
    
    .a6 {
        flex-direction: column;
        align-items: center;
        margin-left: 0;
        gap: 25px;
        margin-top: 20px;
    }
    
    .a7 {
        width: 95%;
        max-width: 450px;
        height: auto;
        padding: 20px;
        text-align: center;
    }
    
    .a8 {
        margin-left: 0;
        width: 95%;
        max-width: 450px;
        text-align: center;
        padding: 20px;
    }
    
    footer {
        height: auto;
    }
    
    .box-9 {
        flex-direction: column;
        height: auto;
        padding: 30px 20px;
        align-items: center;
        text-align: center;
    }
    
    .box-10 {
        width: 100%;
        margin-bottom: 25px;
    }
    
    .box-10 img {
        margin-left: auto;
        margin-right: auto;
        display: block;
    }
    
    .box-10 p {
        width: 100%;
        margin-left: 0;
        padding: 0 20px;
        text-align: center;
    }
    
    .box-11, .box-12 {
        margin: 18px 0;
        text-align: center;
        width: 100%;
    }
    
    .box-14 {
        margin-left: 0;
        margin-top: 25px;
        text-align: center;
        width: 100%;
    }
    
    .box-15 {
        margin-right: 0;
        margin-top: 20px;
        text-align: center;
        width: 100%;
    }
    
    .footer-1 {
        flex-direction: column;
        height: auto;
        padding: 20px;
        text-align: center;
        gap: 12px;
    }
}

/* Mobile - หน้าจอขนาดเล็ก (สูงสุด 767px) */
@media screen and (max-width: 767px) {
    html, body {
        overflow-x: hidden;
        width: 100%;
        -webkit-text-size-adjust: 100%;
    }
    
    nav {
        height: auto;
        min-height: 65px;
        flex-direction: column;
        justify-content: center;
        padding: 8px 10px;
        gap: 8px;
        width: 100%;
    }
    
    .logo {
        order: 1;
        width: 100%;
        display: flex;
        justify-content: center;
    }
    
    .logo img {
        width: 55px;
        height: 55px;
    }
    
    .menu {
        order: 2;
        width: 100%;
        flex-wrap: wrap;
        justify-content: center;
        gap: 6px 10px;
        margin: 5px 0;
        padding: 0;
    }
    
    .menu li {
        margin: 0;
        padding: 0;
    }
    
    .menu a {
        font-size: 11px;
        padding: 5px 8px;
        display: inline-block;
        white-space: nowrap;
    }
    
    .icons {
        order: 3;
        width: 100%;
        justify-content: center;
        gap: 12px;
        margin: 5px 0;
    }
    
    .icons a img {
        width: 26px;
        height: 26px;
        padding: 4px;
    }
    
    .a1 {
        width: 100%;
        height: 280px;
        margin-top: 130px;
        padding-top: 70px;
        border-radius: 0px 0px 350px 0px;
        border-bottom: 60px ridge darkblue;
    }
    
    .a1 h1 {
        font-size: 20px;
        padding: 0 20px;
        line-height: 1.5;
    }
    
    .a2 {
        width: 100%;
        margin-top: 40px;
        padding: 20px 15px;
        gap: 25px;
    }
    
    .a3 {
        width: 100%;
    }
    
    .a3 .img1 {
        width: 110px;
        height: 110px;
        border: #101856 12px double;
        margin-top: 20px;
    }
    
    .a3 .img2 {
        width: 220px;
        height: 220px;
        border: #101856 18px double;
        margin-top: 20px;
    }
    
    .a4 {
        width: 100%;
        padding: 0 20px;
        text-align: center;
    }
    
    .a4 h1 {
        font-size: 20px;
        line-height: 1.4;
        margin-bottom: 10px;
    }
    
    .a4 h2, .a4 h3, .a4 h4 {
        font-size: 16px;
        line-height: 1.4;
        margin: 8px 0;
    }
    
    .a5 {
        width: 100%;
        margin-top: 35px;
        padding: 30px 15px;
        border-radius: 180px 0px 0px 0px;
        border-top: 25px ridge #101856;
        border-bottom: 25px ridge #09188b;
    }
    
    .a6 {
        width: 100%;
        margin-top: 20px;
        padding: 10px;
        gap: 20px;
    }
    
    .a7 {
        width: 100%;
        padding: 15px;
        font-size: 14px;
        line-height: 1.6;
        text-align: justify;
    }
    
    .a8 {
        width: 100%;
        padding: 15px;
        font-size: 14px;
        line-height: 1.6;
    }
    
    .a8 h5 {
        font-size: 16px;
        margin-bottom: 10px;
    }
    
    .box-9 {
        width: 100%;
        padding: 25px 15px;
    }
    
    .box-10 {
        width: 100%;
        text-align: center;
        margin-bottom: 20px;
    }
    
    .box-10 img {
        width: 110px;
        height: 110px;
        margin: 0 auto;
    }
    
    .box-10 p {
        width: 100%;
        margin: 15px 0 0 0;
        padding: 0 20px;
        font-size: 14px;
        line-height: 1.6;
    }
    
    .box-11, .box-12 {
        width: 100%;
        font-size: 15px;
        margin: 18px 0;
        padding: 0 15px;
        line-height: 1.6;
    }
    
    .box-13 {
        width: 100%;
        flex-direction: column;
        align-items: center;
        gap: 18px;
    }
    
    .box-14 {
        width: 100%;
        font-size: 15px;
        margin: 25px 0;
        padding: 0 15px;
    }
    
    .box-15 {
        width: 100%;
        margin: 20px 0;
        display: flex;
        justify-content: center;
        gap: 12px;
    }
    
    .box-15 img {
        width: 40px;
        height: 40px;
    }
    
    .footer-1 {
        width: 100%;
        padding: 18px 15px;
        font-size: 13px;
        line-height: 1.5;
    }
}

/* Mobile ขนาดเล็กมาก (สูงสุด 480px) */
@media screen and (max-width: 480px) {
    nav {
        min-height: 60px;
        padding: 8px 8px;
    }
    
    .logo img {
        width: 50px;
        height: 50px;
    }
    
    .menu a {
        font-size: 10px;
        padding: 4px 6px;
    }
    
    .icons a img {
        width: 24px;
        height: 24px;
    }
    
    .a1 {
        height: 240px;
        margin-top: 120px;
        padding-top: 60px;
        border-bottom: 40px ridge darkblue;
        border-radius: 0px 0px 250px 0px;
    }
    
    .a1 h1 {
        font-size: 18px;
        padding: 0 15px;
    }
    
    .a2 {
        margin-top: 30px;
        padding: 15px 10px;
    }
    
    .a3 .img1 {
        width: 90px;
        height: 90px;
        border: #101856 10px double;
    }
    
    .a3 .img2 {
        width: 180px;
        height: 180px;
        border: #101856 12px double;
    }
    
    .a4 {
        padding: 0 15px;
    }
    
    .a4 h1 {
        font-size: 18px;
    }
    
    .a4 h2, .a4 h3, .a4 h4 {
        font-size: 14px;
    }
    
    .a5 {
        border-radius: 120px 0px 0px 0px;
        border-top: 18px ridge #101856;
        border-bottom: 18px ridge #09188b;
        padding: 25px 12px;
    }
    
    .a7, .a8 {
        font-size: 13px;
        padding: 12px;
    }
    
    .a8 h5 {
        font-size: 15px;
    }
    
    .box-10 img {
        width: 100px;
        height: 100px;
    }
    
    .box-10 p, .box-11, .box-12 {
        font-size: 13px;
    }
    
    .footer-1 {
        font-size: 12px;
    }
}

/* Landscape mode สำหรับ Mobile */
@media screen and (max-height: 500px) and (orientation: landscape) {
    nav {
        min-height: 55px;
        padding: 5px;
    }
    
    .logo img {
        width: 45px;
        height: 45px;
    }
    
    .menu {
        gap: 5px 8px;
        margin: 3px 0;
    }
    
    .menu a {
        font-size: 10px;
        padding: 3px 5px;
    }
    
    .icons {
        gap: 8px;
    }
    
    .icons a img {
        width: 22px;
        height: 22px;
    }
    
    .a1 {
        height: 200px;
        margin-top: 60px;
        padding-top: 50px;
    }
    
    .a1 h1 {
        font-size: 16px;
    }
}